This invention relates generally to vibration damping systems, and, more particularly to a dynamic damping system which aids a positioning servo system to accurately position gimballed objects with respect to inertial space.
It is necessary in many instances, to accurately position with negligible jitter or vibration, large gimballed bodies. For example, in many of today's optical systems it is necessary to maintain, for optical accuracy, a mirror or other optical equipment in stable position with respect to space. In optical systems used in the past, the optical elements (mirrors, etc.) being stabilized were relatively small, and thus possessed low inertias. The consequential coupling resonant frequencies associated with these relatively small elements were high, and were therefore easily removed from the servo loop with electronic filters.
With todays larger aperture systems required for infrared sensors, large mirrors are required for image stabilization. Unfortunately, because the large mirrors have large inertia, relatively low structural natural frequencies result that interact with the mirror stabilization servo loops. For the current family of large aperture systems electronic filtering of the past is not always possible because the filters cause servo instability at the inherently lower natural frequencies. Therefore, the need arises for a dynamic damping system which is capable of providing mechanical filtering without impact on servo stability and thereby permitting servo positioning of objects to a high degree of accuracy.